What can I check beside leaks,spark plugs,coils and connectors on 1999 Ford Expedition

Checked with a Valve Guage Tester and read Late Ingition Timing I have checked for leaks Coil on plugs good Put new spark plugs

by in El Paso, TX on April 12, 2013
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1 answer 2 comments
ANSWER by , April 12, 2013
What are you checking for, tell us what the problem is!
COMMENT by , April 12, 2013
Did a tune up. Started to run with a rough idle and smoking Was not doing this before tune up Rechecked everything to make sure So checked with a gauge and it read LATE INGITION TIMING Also no codes have come out So trying to find out what has caused this It also wants to stall
COMMENT by , April 12, 2013
try dis connect battery for a few minutes. comp. should go to default. might help.